Gasolene-engine.



PATENTED DEC. 18, 1906.- J. WALSH & E. SWANSON.

GASOLENE ENGINE. APPLIOATION FILED 13110.20. 1904.

THE NORRIS PETERS co., wAsrugcronl. P. c.

No. 838,926. 7 PATENTED DEC. 18, 1906. J. WALSH & B. SWANSON.

GASOLENE ENGINE.

APPLICATION FILED 13130.20. 1904.

4 SHEETS-SHEET 2. W

WITNESSES. lNl/E/VTUHS John Walsh 0 A Emil Ewan-son 6 By I ATTORNEYS rHE NORRIS PETERS co., WASHINGTON; u. c.

PATENTED DEC. 18, 1906. J. WALSH & E. SWANSON.

GASOLENE ENGINE.

APPLICATION FILED DBO. 20. 1904.

4 SHEETS-SHEET 3.

' lfVVE/VTORS Joiziz Win28]; E Zz/vans UNITED STATES PATENT OFFICE.

JOHN IVALSH AND EMIL SVVANSON, OF GALESBURG, ILLINOIS, ASSIGNORS OF ONE-THIRD TO THOMAS B. W ALSH, OF GALESBURG, ILLINOIS.

GASOLENE-ENGINE.

Specification of Letters Patent.

Patented Dec. 18, 1906.

Application filed December 20. 1904. Serial No. 237.681.

T0 KLZZ/ whom, it nuty concern:

Be it known that we, JOHN I/VALsH and EMIL SWANSON, citizens of the'United States, residing at Galesburg, in the county of Knox and State of Illinois, have invented a new and useful Improvement in Gasolene-Engines, of which the following is a specification.

Our invention relates to explosive-gas engines of that type known as two-cycle engines,in which by means of two chambers one the cylinder and the other the crankcasethe four acts of admission, compression, explosion, and scavenging are accomplished during one revolution of the flywheel or by two movements of the piston instead of four movements of the piston and two complete revolutions of the fly-wheel, as in the four-cycle engine.

In the ordinary two-cycle engine the piston in moving away from the crank-case compresses the charge in the cylinder and at the same time draws in fresh gas into the crank-case. In the movement toward the crank-case, which is effected by the explosion of the charge, the gas in the crank-case is forced through a by-pass around. to the front of the piston in the cylinder, and in recharging the same a part of the fresh charge is wasted in clearing the cylinder.

In our invention the crank-case is used for compressing a r for scavenging or clearing the cylinder of exploded gases by a prolonged blast through the agency of an automatic pressure-valve, the compression of the explosive charge being effected in an intermediate annular chamber between the cylinder and crank-case, in which an annular piston works, which annular piston is formed on the main piston and moves with it to alternately draw in and compress the charge for explosion.

Our invention consists in the novel construction, arrangement, and combination of parts acting upon the principle described, which we will now proceed to describe with reference to the drawings, in which- Figure 1 is a perspective view of the engine. Fig. 2 is a vertical central section taken lengthwise the shaft. central section taken transversely to the shaft. Fig. 4 is a horizontal section taken on Fig. 3 is a vertical line 4 4 of Figs. 2 and 3, and Fig. 5 is a sec-- tional detail showing a modification of our invention.

In the drawings, Figs. 2 and 3, 1 is the cylinder proper. 2 is a large cylinder forming an annular chamber, and 3 the closed crankcase. In suitable bearings in the crankcase is 'journaled the main shaft S, having its crank .9 arranged within the crank-case. is the piston which works in the cylinder 1 and which piston is formed at its lower end with an enlarged annular piston I working in the annular chamber 2. A cross-pin p within the hollow piston is loosely connected to the upper end of the connecting-rod P and the lower end of the rod connects with the crank s of the main shaft. On one side of the cylinder 1 is formed an offsetting induction-chamber X, which at its upper end communicates with the cylinder through the port a and at its lower end communicates with the annular chamber 2 through the port a. The offsetting chamber X is of relatively large proportions and forms not only an in duction-chest, but the explosion-chamber as well. It extends practically the full length of the travel of the piston P and is arranged parallel with and beside the cylinder-1 and is cast therewith in one piece. Its special value and function will be more fully de scribed hereinafter. A valve B is arranged on a seat in the bottom of the chamber so as to open upwardly and controlling the passage of gas from the annular chamber 2 and port a to the chamber X, port a, and the cylinder 1. This valve has a stem extending through a stuffing-box in the bottom of the chamber X, and a spiral spring B presses against a collar on the valve-stem and holds the valve down on its seat except when positively lifted. This lifting of the valve is effected by a roller F, journaled on an offsetting pin on the valve-stem and riding upon the top of a cam E, keyed to the main shaft. The roller F is carried on a rocker-arm R, Fig. 1, hung upon a horizontal shaft It outside the crank-case.

On the opposite side of the cylinder 1 from the inlet-chamber X is an oifsettingexhaustchamber Y, (see'Fig. 2,) communicating with the cylinder through exhaust-port (L This exhaust-chamber has" an upwardly-opening exhaust-valve A, through which the exploded gases escape to the exhaust-chamber Y and waste-pipe a The exhaust-valve is held down by a spiral spring A bearing on a collar on the valve-stem and is lifted at the proper time by a cam C on the main shaft acting upon a roller D, carried by a pin attached to the lower end of the valve-stem, said roller being also carried on the end of a rocker-arm R hung on the shaft R as seen in Fig. 4:.

For supplying the explosive mixture of gasolene and air a mixing-chamber M (see Figs. 1, 3, 4) is arranged on one side of the annular chamber 2 and opens into the same through an inwardly-opening valve G, whose stem extends outside the mixing-chamber, and is provided with a spiral spring bearing against a collar on the valve-stem, by which the valve is held in closed position on its seat until a suction in the annular chamber opens it.

Into this mixing-chamber (see Fig. 4) is tapped the screw-threaded end of an automatic carbureter or gasolene-feeding device C This feed device consists of a small cylinder having a screw-threaded plug at each end. The screw-threaded plug which enters the'mixing-chamber M is centrally boredto receive a plunger N, and in the side of the plug is a port T, that communicates with a pipe 1) from the gasolene-reservoir. This port T opens near the end of the plunger, so that when the plunger moves back it opens the port and when it moves forward it passes by and closes the port. A small outlet 0 at the end of the central bore allows the gasolene taken in through port T to be forced out by the plunger N into the mixing-chamber M. The plunger N has on its end a piston N, that closely fits the cylindrical part of the carbureter, and a spiral spring 1 wound about the lunger between the piston and the inner ug end, normally holds the plunger back 'or admission of gasolene. On the opposite side of the piston N the cylinder C is closed by an outer end plug which has a screw-threaded hole V, that communicates with a pipe J, which is tapped into communication w1th the annular chamber 2 at a point in the offset below the valve B. Through the end of the plug having opening V an adjusting-screw U is inserted, whose end in the cylinder C is reduced and provided with a spiral spring U, bearing against the piston N.

The lower end of the mixing-chamber M is open at M to take in air, and the gasolene forced through the opening 0 by the feeder mixes therewith, and both are drawn together through the inlet-valve G whenever the annular piston P moves down in the annular chamber. When the annular piston moves up, this mixture of air and gasolene is compressed and forced up through valve B into the ignition-chamber X, where it is exploded by the igniter P, Fig. 1.

We will now explain the automatic action of the gasolene-feeder. (Shown in Fig. 4.)

When the annular piston P goes down in annular chamber 2, it does two thingsit opens the induction-valve G to allow the mixture of gas and air to pass into the annular space, and the artial vacuum that is formed in this annu ar chamber also makes its influence felt through the pipe J upon the piston N of the feeder, causing the piston and its plunger to move back and uncover the gasolene-port. This moving back of the plunger N is effected partly by the suction of the annular chamber on the piston l and partly by the expansion of the spring N on the other side of the piston. When, however, the annular piston P rises and a degree of compression is formed in the annular chamber, the induction-valve G is closed, and the pressure in the annular chamber 2 is felt through pipe J upon the piston l of the gasolene-feeding plunger N, and the latter is forced past the hitherto-open port of the gasolene-pipe, and gasolene is cut off from the pipe, and the small charge of gasolene in front of the plunger is forced into the mixingchamber.

To regulate the admission and. cut off of the gasolene, the screw U is made adjustable in the plug to limit and control the motion of the piston N and plunger l and the spring U cushions the impact of the piston against the screw-stem and avoids a hammering action thereon.

We will now describe-how the discharge of the burned gases, commonly known as scavenging, is effected. This, it will be understood, is effected without the waste of any of the unburned gases and-is effected by a blast of air compressed in the crank-case.

Referring to Figs. 1 and 2, Z is a pipe one end of which. is tapped into the crank-case and the other end of which opens into the chamber X and top of the cylinder 1 through a check-valve I, which opens into the cylinder, so as to allow the passage of compressed air into the cylinder, but will not let the explosion-pressure strike back into the crank case. At an intermediate point in this pipe there is an air-inlet check-valve H, which allows air to pass into the pipe to the crank case, but prevents it from passing out. Now when the main piston rises from the crankcase it will be seen that a suction will be pro duced in the crank-case which draws in air through the valve H. Then when the piston descends the air in the crank-case will be compressed, closing inlet air-valve H, and as soon as the pressure of the exploded gases in the cylinder has fallen (by opening of the discharge-valve) so that the pressure in the cylinder is less than that in the crank-case then the automatic pressure-valve I opens and the remaining traces of burned gases are forcibly blown out of the cylinder by this TCO blast ofair from the crank-case at a time before the fresh charge of explosive gas is admitted.

It will be seen that the introduction of the scavenging blast of air into the working cylinder is entirely independent of any action or movement of the piston. The scavengingblast inlet is always in open communication with the cylinder in all positions of the piston and occurs automatically through pressurevalve I when the pressure in the workingcylinder during the exhaust falls below the pressure of air in the crank-case. This is important, in that the scavenging-blast does not occur in a short puff from a small body of air under high compression, as when such blast is admitted through a port 'or ports controlled by the piston, but is automatic in action, dependent upon the reduction of pressure in the cylinder during the exhaust, and occurs in a prolonged and continuing blast that effectually clears out the burned gases. This scavenging blast is also introduced through the large induction-chamber X in which the igniter is located and which forms a part of the explosion-chamber and through the same port a which admits gas to the cylinder, which not only greatly simplifies coring and cost of construction, but also makes the most effective clearance of burned gases.

In describing the sequence of the several operations of our engine, and referring to Fig. 3, we would state that when the crank is at the position P the engine is just starting to exhaust, and the exhaust continues to the point P the exhaust being accomplished by the action of cam C and roller D onvalve A. During this movement compression has'been taking place in annular chamberZ from the time the crank until the crank reaches the point P, when valve B (see Fig. 2) opens by the action of cam E on roller F. This allows the partlycompressed charge to enter cylinder 1, where it is further compressed until the crank reaches the point P, when valve B closes. At the point P the charge is ignited and the exploded charge has a working effect, forcing the piston down until the crank reaches the point P. The engine then begins to exhaust again for arepe'tition of the same action. \Vhen the crank is at the upper point on center line L K and passing on downward, it creates a partial vacuum in annular cylinder 2, and this causes the charge to enter the said chamber from the mixing-chamber M through valve G. This continues until the crank reaches the lower point of the center line K L, and then the rise of the piston starts the compression in the annular chamber, as already explained,

The above-described action,it will be seen, is similar to that of a two-cycle crank-case engine, except that the annular cylinder 2 takes the place of the crank-case for drawing passes the center line K L in and compressing the explosive gases and the crank-case is used only for scavenging the exploded gases by means of compressed air. In the ordinary two-cycle crank-case engine it commences to exhaust on the downward stroke when about two-thirds of the way down and continues until the engine returns to this point, the fresh charge doing some duty in forcing out the exploded gases and incidentally wasting out with it to some extent. In our engine we avoid this, as we commence to exhaust at the same time as a four-cycle engine, or a little before the center is reached. In this manner we et the benefit of the charge nearly the full stroke and also save the waste of a portion of the freshlyintroduced charge by blowing out the exploded gases by a blast of air from the crankcase.

With regard to the scavenging device we would state this may be slightly modified without in any way changing the principle of the invention. Thus, for instance, the pipe Z between the inlet air-valve Hand the chamber X may be dispensed with, and the valve I instead of being in the pipe Z, as shown, may be located in the piston itself, as shown at I in Fig. 5. This valve I allows the compressed air in the crank-case to pass up into the cylinder 1 in the same manner and for the same purpose that the valve I does in Fig. 2. In such modification the crank-case may have asimple inlet check-valve H, located at anysuitable point. We prefer,however, the external pipe Z with the air-intake valve H located in the pipe Z a little more than half-way up the pipe, for the reason that the air in pipe Z below valve H then moves alternately into and out from the crank-case, and thus sweeps back into the crank-case the oil which is contained therein for lubrication and which is splashed into a spray, thus preventing the oil from creeping up the pipe, as it would if the air were taken into the crank-case at another point.

In setting forth the advantages of our invention we would state that we get a better compression, a better expansion, keep the exhaust-valve closed a longer time, and produce a more powerful two-cycle engine, resembling in its efficiency the four-cycle engine. We also save all the explosive gases for useful purposes and get a better scavenging effect by utilizing a prolonged blast of air from-the case for this purpose. I/Vith re gard to the value and function of the enlarged induction and explosion chest X we would state that it shortens the length of the port between the lower cylinder and explosion-chamber, thus leaving less gas below valve B in case it should be accidentally ignited, as sometimes happens in two-cycle engines. It also gives a better expansion of the exploded charge, because it is the main explosion-chamber, and when the piston P rises it passes a little over the edge of the port a, leaving a very small space above the piston in the upper cylinder, so that when the charge is exploded in chamber X it rushes into cylinder 1 and follows the piston more gradually with a longer expansion-line, and there is less shock, and the pressure does not fall so rapidly. We also get a shorter and quicker passage of gas to the explosion-chamber with less friction to the flow, as well as a better scavenging effect, as before described. Furthermore, We are enabled to shorten the length of the cylinder and valve motion, which is a great desideratum where compactness is desired, as in marine engines.

Our engine will start as well as a four-cycle engine, as the crank-case does not have to be filled with gases before starting. Our engine can also be crowded or overtaxed more than a four-cycle engine, since it gets an impulse at every revolution. Our carbureter is also directly and automatically operated by the pressure and vacuum of the annular chamber, and is therefore specially correlated thereto and timed in its action thereby. It is also of very simple construction and is ad justable to regulate the charge.

- It will be obvious that our engine may be constructed in multiple units of any number of cylinders to give increased power, as may be desired.

Having thus described our invention, What we claim as new, and desire to secure by Letters Patent, is

1. A two-cycle explosion-engine, comprising a two-diameter cylinder and a two-diameter piston, an enlarged induction and explosion chamber arranged beside the smaller cylinder and opening permanently at one end into the end of the said small cylinder and having at the other end an intake-valve from the large-diameter cylinder, an igniter lotwo cylinders of different diameters and a two-diameter piston fitting the same and forming an annular vacuum and compression chamber, a carbureting device communicating with said annular chamber and having a pneumatically-operated plunger for 'feeding the liquid fuel and a pipe connecting the carbureter with the annular vacuum and compression chamber to operate the feed-plunger of the carbureter by the impulses of-pressure and suction in the annular chamber substantially as described.

3. A two-cycle explosion-engine having a 'carbureter with a pneumatically-operated separate ignition-chamber with an inlet gasvalve opening into the same from the larger compression portion of the cylinder and an external scavenging-pipe tapped at its lower end into the closed crankcase, and at its upper end into the ignition-chamber, an airinlet valve located in said pipe near its middle and an automatic pressure-valvelocated in the upper end of said scavenging-pipe and opening the latter into the ignition-chamber.

5. A two-cycle engine having a tw0-diameter cylinder and piston, a separate ignitionchamber arranged beside the working pistonchamber and'a scavenging air-blast with automatic pressure-valve tapped into the separate ignitionchamber.

6. A two-cycle engine having a two-diameter cylinder and piston, a separate ignitionchamber beside the working piston-chamber, a closed crank-case, an external scavengingpipe connecting the crank-case with the ignition-chamber, an air-intake valve located about the middle of said pipe and an automatic pressure-valve opening from said pipe into the ignitionchamber for scavenging through the ignition-chamber.

JOHN WALSH. EMIL SWANSON.

Witnesses:

EUGENE W. WELCH, T. B. WALSH. 

